A lot of times, the display is included with the merchandise order, especially for a large national company, to maintain an easily recognized icon. Usually, they are designed by the company's marketing department and made by a sub-contractor exclusively for that company. They also have other merchandising items available for the retailer to purchase, or for the sales rep to include as incentives for a larger order. The prices are set by the factory, but the sales reps can use their ingenuity to drum up more sales, like including a free sign or display case for a certain sized order.